My invention relates to a method for producing metalurgical addition agents and more particularly, a method of producing metallurgical addition agents such as silicon carbide which method employs a high percentage of fines as the staring material.
A number of manufacturing processes develop fines as a by-product which, if consolidated, can be used in melting furnaces and the like as alloy additions. Various processes for consolidating these fines are known and certain of these processes use cement as a binder. For example, U.S. Pat. No. 3,174,846 teaches a method of briquetting iron oxide fines through a standard roll-type briquetting press. U.S. Pat. No. 4,148,627 teaches a method of agglomerating particulate steel mill wastes, such as roll scale and coke fines by mixing the materials with Portland cement and casting into slabs which are thereafter broken and screened for charging into the furnace.
U.S. Pat. Nos. 3,871,869 and 3,027,227 are directed to method for pressing briquettes from fine grained fluorspar in which cement is a binder.
A particularly important metallurgical addition agent is silicon carbide which has a number of applications in the manufacture of cast irons and steels. U.S. Pat. No. 3,051,564 teaches a composition for making silicon carbide briquettes, which composition includes metallurgical grade silicon carbide and Portland cement.
It is also known to make silicon carbide on concrete block machines using cement as a binder. The shortcoming of using the concrete block machinery, is that only up to 25% fines can be employed because the machinery becomes "gummed" with the fines and will not function properly. Other processes which employ fines in excess of 25% utilize briquetting rolls and require elevated temperature cures to effect a proper consolidation.